(a) Technical Field
The present invention relates to a starting device for high-voltage components of a vehicle, particularly a fuel cell vehicle. More particularly, it relates to a starting device for high-voltage components of a fuel cell vehicle and a method for controlling the same, which can improve starting performance during start-up of the fuel cell vehicle by providing a separate starting means, which is driven by the power of a 12 V battery, in high-voltage components equipped in the fuel cell vehicle.
(b) Background Art
A typical fuel cell system applied to a fuel cell vehicle comprises a fuel cell stack for generating electricity by an electrochemical reaction between reactant gases, a fuel supply system for supplying hydrogen as a fuel to the fuel cell stack, an air supply system for supplying oxygen containing air as an oxidant required for the electrochemical reaction in the fuel cell stack, and a thermal management system for controlling the operating temperature of the fuel cell stack.
Each of the above systems of the fuel cell vehicle comprises a high-voltage component. For example, the air supply system comprises an air blower, and the thermal management system comprises a water pump.
The high-voltage components, such as the air blower, water pump, etc., cannot be driven directly by the power of a 12 V battery. Thus, they are driven by a high voltage generated by boosting the voltage of the 12 V battery, and then they are operated by the power generated from the fuel cell stack during normal operation.
Therefore, during start-up of the fuel cell vehicle, a DC-DC converter for generating a high-voltage by boosting the voltage of the 12 V battery is required for the operation of the high-voltage components.
FIG. 3 schematically shows the configuration of a fuel cell stack mounted in a fuel cell vehicle, and an air supply system for supplying oxygen containing air to the fuel cell stack.
As shown in FIG. 3, during start-up of the fuel cell vehicle, a high voltage is generated by boosting the voltage of a 12 V battery 16 at a DC-DC converter 18, and is supplied to an air blower 14 (a high voltage component) through an air blower controller 12.
Then, the oxygen in the air is supplied to a fuel cell stack 10 by the operation of the air blower 14 and, at the same time, hydrogen is supplied from a fuel supply system to the fuel cell stack 10 such that the fuel cell stack 10 generates electricity.
When the fuel cell stack 10 normally generates electricity, the air blower 14 is driven by the power generated from the fuel cell stack 10.
However, the DC-DC converter 18 is necessarily used to boost the voltage of the 12 V battery 16 during start-up of the fuel cell vehicle. This causes a number of problems.
First, the DC-DC converter 18 needs a large installation space and causes some problems such as reduction in fuel efficiency, heat generation, etc. during power conversion.
Moreover, although the high voltage generated by boosting the voltage of the 12 V battery 16 at the DC-DC converter 18 is supplied to the air blower 14, the rotational speed of the air blower 14 during initial operation is about 7,000 to 8,000 rpm. This is lower than the designed value, and thus the operation efficiency is reduced.
In particular, as shown in FIG. 4, the high voltage generated by boosting the voltage of the 12 V battery 16 at the DC-DC converter 18 is supplied to a high-voltage motor 22 of the air blower 14. At the same time, a compressor 24 having the same axis as the compressor 24 is driven to compress air. However, the rotational speed of the high-voltage motor 22 during initial operation is about 7,000 to 8,000 rpm. This is lower than the designed value, and thus the operation efficiency is reduced.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.